Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Short Brothers Model SD3 series airplanes. This proposal would require testing for stiffness of the aft pintle pin bushing of the main landing gear (MLG), and inspecting and measuring the aft pintle pin bushings of the MLG for damage, and for out-of-limit dimensions of the bushing bore. This proposal would also require corrective action if necessary. This action is necessary to detect and correct corrosion and deterioration of the aft pintle pin bushings of the MLG. Corrosion and deterioration of the bushings, if not detected and corrected, could result in the MLG not extending fully during landing, with consequent damage to the airplane structure. This action is intended to address the identified unsafe condition.